266-126-FN-A03 for Grendel

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  • #489889
    louielindenmayer
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      I have a Bear Creek Arsenal 18″ Grendel upper, HDY brass, WW-SRP and a few lbs of Accurate 2495.
      The BCA is somewhat over-gassed so even with an H3 buffer and an adjustable gas block the action still functions with lower-power loads.
      I had contact Western Powders (‘Labby’ from their website) about the omission of A2495 from their manual and within an hour they replied that the bulk density wouldn’t allow filling to max pressure which sounds good to me: A2495 is very clean burning even at lower pressures, burns a little cooler and is easy to ignite.
      Using RanchDog-supplied Quickload data I started with 24.7gr & 24.9 gr which is just over 2000 fps, 90% loading density, cycles the action reliably, no unburnt kernels and easy cleaning.
      The bullets had been PC-coated w/Harbor Fright Red and sized to 0.2655″ with HDY gas check but not weight-sorted.
      While I’m still just function testing, the 24.9gr load appeared to be grouping – as opposed to scattering – and within a couple MOA of my jacketed bullet load so as I refine my technique, weight sort the bullets I’ll report back some results.
      A4064 is another possibilty and AR-COMP is on my list, too.

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    • #511640
      louielindenmayer
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        After powder coat and gas check, weighed & used bullets 126.3 +/- 0.3 grain, the HDY brass and WSP loaded to 2.126″ COAL +/- 0.001″
        Range was 42 degF and wind > 5 mph
        Powder was Accurate 2495 and 3-shot groups for basic ladder testing and all loads cycled action to pick up the next round:

        WT    24.9  25.1  25.3  25.5  25.7  25.9  26.1
        AVG  2042  2059  2088  2090  2106  2110  2130
        SD      26    10    9    21    7    15    17

        25.7 grains gave the best group (1.25″) while the rest had 2 shots almost touching with one flyer. After adjusting some of the QuickLoad parameters for this powder, the predicted velocities were within 20 fps becoming closer as pressure got over 30k psi

        Charge  Vel.  Energy  Pmax  Pmuz  Prop.Burnt
        Grains  fps  ft.lbs    psi    psi      %
        24.90  2024    1148  27004  8242    94.8
        25.10  2043    1170  27751  8317    95.2
        25.30  2062    1192  28517  8390    95.6
        25.50  2081    1214  29302  8461    96.0
        25.70  2100    1236  30107  8529    96.3
        25.90  2119    1258  30932  8596    96.6
        26.10  2138    1281  31778  8661    97.0

        #511641
        louielindenmayer
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          OK, one last chart relating the charge weight to velocity – there seems to be some possibilities at 25.4 & 25.8:

          #511642
          louielindenmayer
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            While the next group of PC bullets was about 127.3 gr +/- 0.3 grains, the 25.8gr/A2495 definitely shot a tighter 10-round group w/o the Magnetospeed.
            One thing worth mentioning is that the barrel was still shiny and only a little powder residue (the A2495 is delightfully clean burning) but when I removed the 3-port muzzle brake there did seem to be a little ridge of some substance that was easy enough to brush away.
            Probably need to test w/o brake and/or possibly thread protector but a new trigger to replace this mil-spec one would be nice.

            #511643
            AlvinYork
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                This is all good stuff, LouieLouie. I got to a certain point with my Grendel then moved on to other projects. I will get back to it, probably sooner rather than later. I don’t have any A2495 but based on what you’re saying I think I’m going to pick up a pound to see how it works out for me.

              #511644
              louielindenmayer
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                Just a slight update: using the current version of Gordon’s Reloading Tool (1812) and while there was no entry for A2495 I was able to create a basic profile from A4064 with some adjustments from QuickLoad for basic volumetric values, heat indices, etc. but the one thing that GRT has is a way of adjusting the burn rate to match the actual observed velocities plus predict OBT accuracy nodes. Once the values for the powder profile were dialed in, the predicted OBT actually matched the 25.8 gr prediction from the chart above – the next higher node is predicted to be 26.4 gr @ 2,216 fps with 35k psi of pressure.
                I’ve fed back some data to the GRT team for some other powders (like H100V) and will probably send this to them also. I’d also like to try the 140 gr version of this bullet (266-140-FN-BM3) since the 266-14-FN-BY3 (for my 260 Rem and 6.5×284) needs to be seated too deep.
                BTW, I’ve given up on the 18″ BearCreekArsenal barrel and moved to a 20″ 5R 1:8 Green Mountain barrel sourced from BluntForceTrauma of the 65Grendel forum.

                #511645
                louielindenmayer
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                  Since I’m about out of A2495 I’d like to report that with 26.1 gr I could reliable get 2,146 fps and 2 MOA – and functioning in my AR – suitable for a 4″ plate @ 125 yds to get some quality trigger time. This combo runs really clean.
                  I’ve been Hi-Tek coating now and boolits are running about 128.4 gr loaded to 2.125″. To save my brass I bought an Anneeleez and may go to a bushing die.
                  ShootersWorld AR-Plus give about 80% load density, 100% burnt propellant and still runs approx 40k psi for 2,220 fps so I’ll be playing w/that soon.

                  #511646
                  Mike B.
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                    Thank you for your detailed intel on the 226-126-FN in the 6.5 Grendel.
                    Feeding your data into QuickLoad appears to show the following.
                    Please see the attached intel below.
                    For the specifications as noted in the attachment the max pressure generated by your load as predicted by QuickLoad was 33268 PSI.
                    To augment that data I then ran the computer prediction for the remaining powders using the QuickLoad ShootersWorld pro powder program provided by ShootersWorld for QuickLoad.
                    That complete file of the top 100 of the cleaner burning powders file unfortunately was too large for the NOE forum to accept.
                    If you want to reply and ask about the other specific powders that the the ShootersWorld QuickLoad predicted would burn clean please reply with that powder type.
                    NOTE to those responding.
                    In order for the QuickLoad predictions to be accurate you will need to follow the COAL dimensions including the details as specified in the original forum reply #6 on 1-7-21, & the SAAMI specs.
                    Like everything else…. Please use the projected data provided at your own risk.

                    Please also check the data provided against any reloading manuals and powder mfg sources that are available.
                    I have no control on the procedures that you may use to reload your cartridges.
                    Take Care & Stay Safe.

                    #511647
                    louielindenmayer
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                      According the the “Propellant Profile” in the 2/21 Handloader magazine, ShootersWorld AR-Plus was meant to be a cleaner, flash-suppressed and more temp-stabilized version of H335 and it has performed well in my 223. It was also mentioned that it is not as position-sensitive so 80% load density shouldn’t be too much of a problem for cast bullets.
                      To conserve my small rifle primers I bought some “once fired” 7.62×39 brass (large primer that I have lots of) and the resulting case capacities of H2O AFTER firing *IN MY CHAMBER* are as follows:

                      Hornady 6.5 Grendel (control) – 37.1 gr
                      PPU 7.62×39                          – 36.5
                      Fiocchi 7.62×39                      – 36.3
                      S&B 7.62×39                          – 36.0
                      GECO 7.62×39                      – 35.9
                      Winchester 7.62×39                – 34.9

                      With a 6% difference in case capacity you have to be EXTRA careful to be mindful of pressures – my target velocity of 2,200 fps had charge weights range from 24.1 to 24.8 to stay around 36k psi – according to GRT. There’s an “OBT” node right about there with my 20″ barrel.
                      The other thing to be aware of is that I annealed all the brass (AnneelEez) before initial sizing and each brand has slightly different necks which affect seating depth – I was trying for 2.124″ +/- 0.002
                      BTW, GordonsReloadingTool has a function that measures the burn rate of your lot of powder from your actual velocities – assuming all your other data points are accurate. The difference I saw was about 1% from the default value which is typical.
                      When the wind and snow die down I’ll get some velocity numbers but it still provides some very useful off-hand shooting at steel plates.

                      #511648
                      louielindenmayer
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                        I have some limited data to share – using the target of an OBT (Optimum Barrel Time) of 1.3096 ms for my 20″ barrel (value figured by QuickLoad and GordonsReloadingTool) and adjusting the load for the brass volumes in the previous post l was trying to achieve about 2,200 fps. The values with the various brands are:
                        S&B 2,266 (CCI 200)
                        Fiocchi 2,262 (S&B LR)
                        GECO 2,259 (S&B LR)
                        PPU 2,252 (S&B LR)
                        All of these measured on my Magnetospeed with an Sd of 13 and ES of 35 for 5 shots
                        The conundrum was W-W brass & S&B primers – 2,235 avg, Sd 38 and ES 95 and I have no idea but I’ve never been happy with W-W 7.62×39 for cases.

                        GRT had a predicted velocity but the results were higher so a function to recalculate the burn rate was used and an increase of 0.7% over “stock” was used to calculate new charge weights which were about 0.1 ~ 0.2 less.
                        I was pleasantly surprised about the temp stability w/this batch of AR-PLUS and noted that S&B primers have always been ‘softer’ than CCI 200’s and works to about 250 psi less in “initial pressure” value.

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